Axiom Home Page Forums General Discussion Technical Questions What am I missing with my ep350?

Due to work commitments, I've been away from home for most of the last year. Christmas came, my wife bought me a nice new TV :), I've got time on my hands again and I've had a chance to watch some movies and spend a lot of time listening to music. And somethings been missing...

Although I probably should have realized it was the sub, I was getting some LFE during movies so it didn't initially jump into my head.

My initial thoughts were that one of the kids may have adjusted the setup (although they do know better) but everything was as I left it.

I went through my setup from the beginning again.
- sub crossover to 120Hz
- receiver crossover to 80Hz
- sub volume to 10 o'clock to start
- sub in phase
- all speakers set to small

At 10 o'clock I get nothing, and the sub won't even wake up on its own. By 2 o'clock I start to get the really big LFE effects, but even at max volume, I don't get any bass other than the LFE channel on DVD and nothing off CD.

From there, I worked back to the amp. I checked continuity on my sub cable which seems fine. I changed my sub cable out with another 75ohm cable I had on hand. I checked the sub preamp out on the receiver with my voltmeter and I do register a signal.

My next move was to bypass the receiver altogether and feed the CD player directly to the sub input. Nothing.

Is my subwoofer amp hooped?

Am I completely missing something?

Is there something else I can check?

Thanks.

endish,

Have you checked the SW receiver trim level on your Yamaha. This setting could have been turned down which could lead to low output and also lead to the auto/on not being able trigger. What level is that set to on your Yamaha.

Good luck!

The SW trim level seems fine. It's currently set 3 ticks above 0, which is higher than any of the speakers which vary from -1 to 2.

120Hz is the max crossover for the sub, so that should be out of the picture.

Try boosting the level on the reciever a tad more and see if that helps at all.

Endish, I've been hesitating in replying until I could think of something sensible, but decided to reply anyway. As Dr.Horse suggested, temporarily set the sub trim on the receiver all the way up to see if that "wakes up" the sub amp.

One puzzling thing is the failure with the CD player direct to the sub. That would seem to indicate that the amp was shot, but you say that some LFE was experienced from the sub during movies, so the amplifier has some life, but seems to require an unusually high voltage input(higher than the CD player could provide)to turn on.

*giggle*

Have you tried unplugging the sub from the outlet and letting it sit for a bit before you plug it back in, a year is a long time.

I haven't, but what might that accomplish?

I will try bumping the level tomorrow. I missed the kids' bedtime limit for tonight

It'll recalibrate the phased flux capacitor to the inverted tachyon field array.

Sometimes electronics just need a reboot. Granted, there's not much in a sub that ought to require a reboot, but it's worth a shot. Something easy to try, anyway.

I can think of a couple of other ideas.

1) Turn the sub's crossover all the way up, as high as it will go. To 'bypass' if that's an option. You want the receiver doing the crossover duties, not the sub.

2) Double check all of your connections & wiring. Make sure your sub cable isn't falling out somewhere or has a break in it. I'd physically disconnect & reconnect every cable in the chain. But since you're seeing voltage with the voltmeter, I don't know - sounds like you're all good on the connections front. Perhaps double check the connections & switches on the sub itself. Is there an auto-turn on setting? Perhaps jiggling that switch a bit might help. If the switch has an 'On' position, try that instead of 'Auto'. See if that makes any difference.

3) Have you tried calibrating your system with an SPL meter? It may not solve the problem, but it would give you some idea of how many DB 'cold' the sub is compared to the rest of your speakers. I don't know anything about Yamaha receivers, but your description of the settings does sound like it ought to be working.

4) Make sure the receiver isn't in some 'midnight' mode, where it's attenuating the output.

5) If it won't cause you too much stress, as a last-ditch effort you could do a full reset on the receiver. Sometimes settings get messed up and it could be hard to diagnose what it is. Resetting it would let you start from scratch. Yes, you'd have to set it all up again, potentially a PITA. I'm not very optimistic that this would solve anything, but it's something.

But again, since the sub didn't work with the CD player, that would almost have to indicate that the problem is in the Sub. Would a CD player provide enough output voltage to trigger a sub? I don't know. Anyone?

Good luck.